Field of the Invention
The present invention relates to a stripping solution for photolithography which can be suitably used in manufacture of semiconductor elements such as IC and LSI as well as liquid crystal panel elements, and to a method for forming a pattern using the same.
Related Art
When semiconductor elements such as IC and LSI, or liquid crystal panel elements are manufactured, a CVD vapor-deposited metal film or an insulating film such as an SiO2 film is first formed on a substrate such as a silicon wafer or glass. Next, a photoresist composition is uniformly applied on the metal film or the insulating film to form a photoresist film, and this photoresist film is selectively exposed and developed to form a photoresist pattern. Then, the substrate is subjected to an etching treatment using the photoresist pattern as a mask to form a fine circuit. Thereafter, the photoresist pattern is ashed, and residual materials of the ashed photoresist pattern, and etching residual materials are stripped away using a stripping solution for photolithography.
It is to be noted that aluminum (Al); an aluminum alloy (Al alloy) such as aluminum-silicon (Al—Si), aluminum-copper (Al—Cu) or aluminum-silicon-copper (Al—Si—Cu); titanium (Ti); a titanium alloy (Ti alloy) such as titanium nitride (TiN) or titanium tungsten (TiW); tantalum (Ta), tantalum nitride (TaN), tungsten (W), tungsten nitride (WN), copper (Cu) or the like may be used as the metal film described above. Furthermore, not only the metal film and the insulating film, an interlayer insulating film such as an organic SOG (spin-on glass) film may be also adopted. The metal film, insulating film, interlayer insulating film and the like are formed on the substrate as a single layer or a plurality of layers.
The stripping solution for photolithography is desired to have an ability to effectively strip residual materials of a photoresist pattern and etching residual materials, and be superior in anticorrosion properties on metals. In order to achieve both performances, use of hydrofluoric acid and a compound containing ammonia as a counter amine thereof (see Patent Documents 1 to 3), hydrofluoric acid and a compound containing 1,8-diazabicyclo[5.4.0]undecene-7 as a counter amine thereof (see Patent Document 4), or the like has been proposed so far.
Patent Document 1: Japanese Unexamined Patent Application, Publication No. 2001-83713
Patent Document 2: Japanese Unexamined Patent Application, Publication No. H9-197681
Patent Document 3: Japanese Unexamined Patent Application, Publication No. 2000-47401
Patent Document 4: Japanese Unexamined Patent Application, Publication No. 2000-181083